MediumStatisticsst-162

IRT 1PL Probability

Problem

Return the one-parameter logistic probability 1/(1 + exp(-(theta - b))).

Hint

The 1PL is the Rasch model with a single difficulty parameter.

case 1

in: [0,0]

expected: 0.5

case 2

in: [1,0]

expected: 0.7310585786300049

case 3

in: [0,1]

expected: 0.2689414213699951

case 4

in: [2,-1]

expected: 0.9525741268224334

case 5

in: [-5,5]

expected: 0.000045397868702434395

Starter codePython

import math
def irt_1pl_probability(theta, b):
    # Your code here
    pass

5 test cases · run your code against them in the editor